Award for submarine rescue system
2006-11-16
David Joshua
THE company HG Molenaar Engineering in Paarl, working with Divex of Cape Town, scooped the award as Overall Winner, as well as Winner in the Project category, at the recent 2006 Stainless Steel Awards, hosted by the SA Stainless Steel Development Association (SASDA).
Being a world-first for the South African fabrication industry, Molenaar and Divex formed part of an international project responsible for the development of an ultra-modern submarine rescue system for deployment in maritime waters under jurisdiction of the North Atlantic Treaty Organisation (NATO).
“Strict specifications placed considerable demands on the manufacturing process. This showcased our country’s ability to meet global standards,” says board chairman Cor Molenaar, echoing the words of panel judges at the awards.
“The project meant a lot to the local stainless steel industry, but our entire country can be proud of it.”
The aim of the rescue system is to evacuate crew from a stranded submarine within 72 hours anywhere in the world, without any decompression affecting the crew.
Designed by the Scottish and SA company Divex, defence contractor and world leaders in diving equipment technology, the 100 cubic metre hyperbaric submarine rescue system consists of three hermetically connected pressure vessels, capable of accommodating 72 persons.
Cutting down on weight as it has to be flown to its deployment site, it is made from 5mm SAF 2205 duplex stainless steel.
Vessel one is 2.,1m in diameter, 5m high with four manways and more than 30 penetrators and a huge array of lugs and stand-offs.
Vessel two and three are 1,8m in diameter, twelve metres long with two compartments.
All of them are equipped with electricity and electronic communications connections, can decompress its entrance chamber so as to airlock and to admit or discharge staff.
They also have separate small airlocks so that medicines, food or tools can be passed in and out without decompressing either chamber.
In the event of a submarine sinking somewhere in the world, the rescue system owned by the UK, French and Norwegian governments will have the entire rescue spread, including the decompression assembly, mobilised and loaded onto airplanes and flown to a suitable ship in the harbour nearest the stricken sub.
The crew of the sub are rescued in a submersible, mated with the central chamber to achieve a hermetic seal, transferring the crew and commencing decompression under controlled operating procedures.
The submersible then resubmerges to recover the next batch of submariners.
“The achievement in the building of the pressure vessel bodies lay in the constraints on the manufacturing,” said Martin Molteno, technical manager of Molenaar’s.
“It had to be built to PD5500 specifications and Lloyds shipping rules with full manufacturing surveillance. Material had to be certified to 3,1 degrees Celcius and impact-tested at -21 degrees Celcius.”
Together with this all welds had to be 100% X-rayed, zero defects were allowed and all welds had to be done by manual TIG (a very slow process) in a very short time.
“In spite of all of the stringent requirements, all three of the vessels progressed through manufacture within minimal difficulties and ultimately passed all their hydro tests in Paarl, first time,” said Jaco MacLachlan, project manager, and Arthur van Rooyen, responsible for quality control.
Tests were witnessed by Molenaar’s, Divex Cape Town and Aberdeen, Rolls Royce, the British Department of Defence (for NATO) and Lloyds Shipping.
More
News
|
